Manufacturer does not recommend flushing A/C system. If system is contaminated, discharge system and install a liquid line filter between condenser and evaporator.
Filter may be an integral part of the line, or line may need to be cut and filter installed (non-integral type). Filters may or may not contain orifice. See Fig 1 .
Filter with orifice is installed on low pressure side of orifice tube. Remove original orifice tube if installing filter with orifice. Filter without orifice must be installed on high pressure side of orifice tube.
To install liquid line filter, discharge A/C system using approved recovery/recycling equipment. Remove liquid line. Using a tubing cutter, cut section from liquid line to allow installation of liquid line filter. Clean all burrs, and smooth surfaces.
Install nut over line. Install ferrule on line with small end toward nut. DO NOT install "O" ring at this time.
Push line into fitting until it bottoms on filter assembly. Tighten nuts on each joint to 11 ft. lbs. (15 N.m). Disassemble joint assembly.
Lubricate new "O" rings with refrigerant oil and install them on lines. Install filter assembly. Ensure arrow on filter indicates proper flow of refrigerant. Tighten nuts to 11 ft. lbs. (15 N.m). Evacuate and charge system. Check system for leaks.

Fig 1: Exploded View Of Liquid Line Filter & Components

Courtesy of GENERAL MOTORS CORP.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

General Motors